You can rebuild it. It is very easy. Is the starter "dragging" badly? If not, then you can disassemble and replace brushes and bushings.
The chassis overhaul manual only has 6 pages on it. I can scan and email to you if you wish.
Most of it you won't need anyway. 99% of the time, you need to replace the front bushing, lube the rear bushing (they rarely wear out), replace the brushes, and clean the armature. You DON'T need to turn down the armature most of the time. I am talking like one out of a thousand.
BTW, as I stated on another site, I really like silver and black. You need to post some more pics of that car.